1. Field of the Invention
The invention relates to image processing and, more particularly, relates to off-grid interpolation performed in image processing.
2. Related Art
Conventional image processing systems that perform interpolation within a Bayer pattern seek to perform interpolation to generate a triplet that is located actually on the various pixel locations within the Bayer pattern. For an illustrative example, four of the centrally located pixels within the 5×4 pixel Bayer pattern shown below are used to create RGB triplets using this conventional approach.
The four bold faced locations within the Bayer pattern shown below:
R0, G0, R1, G1, R2
G2, B0, G3, B1, G4
R3, G5, R4, G6, R5
G7, B2, G8, B3, G9
can be used generate the following RGB triplets:
    (¼*(R0+R1+R3+R4), ¼*(G0+G2+G3+G5), B0) (½*(R1+R4), G3, ½*(B0+B1))    (½*(R3+R4), G5, ½*(B0+B2)) (R4, ¼*(G5+G3+G6+G8), ¼(B0+B1+B3+B2))
Alternative methods of performing the RGB generation within the Bayer pattern are also performed in conventional interpolation image processing systems as shown below.    (½*(R1+R3), ½*(G0+G5), B0) (½* (R1+R4), G3, ½*(B0+B1))    (½*(R3+R4), G5, ½*(B0+B2)) (R4, ½*(G3+G8), ½*(B1+B2))
Depending on how many adjacent or neighboring pixels are to be used, the color shown by the RGB triplet may or may not be an accurate representation of the actual image that was acquired by the mask. Other methods of performing the generation of on-grid RGB triplets are also performed in conventional image processing systems.
In addition, the conventional methods of performing on-grid interpolation result in other perceptual and qualitative deficiencies. For example, for very thin lines within an input image, the intensity of the line is sometimes inconsistent, and it even becomes a broken line in some cases. In addition, non-uniformity in the image due to mismatches of the mask performing the image acquisition can also result in mosaic-type of images within conventional image processing systems. Moreover, cross talk between adjacent pixels within the mask, during image acquisition, can also result in many undesirable artifacts within the input image. Each of these deficiencies result in the deleterious effects of improper and often poor image representation using RGB triplets of a Bayer pattern distributed mask.
Similarly, gray scale images will suffer from deleterious effects such as inconsistent line intensity and sometimes being shown as a broken line when performing on-grid interpolation as known in the art of image processing.